This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Polymers are synthesized and crosslinked using tyrosine through the formation of dityrosine. Fluorescent spectrum scans are performed to see if tyrosine and dityrosine can be individually identified within a mixture of digested polymer due to different emission peaks. Further analysis would be needed to quantify the concentration within each mixture.